The good news: PPP Menu 2.0.1 is now available. The authors claim that it fixes "99.9% of the bugs reported."
On related news from Rockstar: FreePPP 2.6 beta is now available. Steve Dagley writes: "The most important fix for this release eliminates the problem with crashing in the getbuffer routine on a very busy connection. This fix is courtesy of Craig Prouse from Apple who identified the cause as a bug in the original MacPPP code which FreePPP is based on. If your Mac ever crashed or hung while you were surfing the Net using FreePPP or MacPPP odds are this bug is what bit you."
FreePPP 2.5v3 should be out by April 15. The only addition to 2.5v3 is "A bug was fixed that caused users with wireless modems to crash." (Thanks also, Steve Stitle.)